Mapping CD20 molecules on the lymphoma cell surface using atomic force microscopy

Atomic force microscopy (AFM) was used to locate CD20 molecules on the surface of lymphoma Raji cells. Rituximab (a monoclonal antibody against CD20) molecules were linked onto the AFM tip via a polyethylene glycol (PEG) linker. Raji cells were adsorbed onto glass slides coated with poly-L-lysine. First, the CD20 distribution in a local area of the cell surface was visualized using the AFM lift scan mode. Second, 16 × 16 force curves were obtained from the same cell area to construct the CD20-rituximab binding force map. Finally, free rituximab was added to block the CD20 molecules on the cell surface and the lift phase image and CD20-rituximab force map were obtained again. The experimental results indicated that when the lift height was greater than the length of the PEG linker, no recognition sites were observed in the lift phase image. However, as the lift height decreased to the length of the PEG linker, some recognition sites were observed in the lift phase image and these sites were generally consistent with the pixels in the force map. After blocking, both the recognition sites in the lift phase image and the gray pixels in the binding force map decreased markedly. These results can improve our understanding of the distribution of protein molecules on the cell surface and facilitate further investigations into cellular functions.     

宽带薪酬设计

宽带薪酬设计的定义 宽带薪酬始于20世纪的90年代，是作为一种与企业组织扁平化，流程再造等新的管理战略与理念相配套的新型薪酬结构而出现的。     

关于(m,n)-内射模与(m,n)-平坦模的几点注记

定义了（m，n）-半遗传环与（m，n）-正则环，（m，n）-内射维数和（m，n）-平坦维数，其中m，n是两个正整数．并用这两种维数对以上两种环进行了刻画．     

雇佣军：未来战争的形式？

20世纪80年代，一部描写雇佣兵的电影——《野鹅敢死队》深深地烙在了一代人的记忆里。电影中的雇佣兵受雇去改变一个非洲小国的政局，如今，真人版的类似故事也在现实中不断上演。自利比亚3月份遭到北约空袭以来，尽管卡扎菲的多个下属，甚至对外代表着利比亚国家的外交官纷纷弃他而去，但1．6万来自几个不同国家的非洲雇佣军却誓言要捍卫他直到“最后一刻”。     

舍己救人的名医——格林菲尔

1．19世纪末20世纪初，英国伦敦一位名医心甘情愿地放弃城市的优裕生活，到加拿大的寒地为渔民服务，获得了世界上最宝贵的东西——“快乐”与“知足”。他，就是英国名医格林菲尔。     

从句容试点项目看20KV配电网的经济性

随着江苏经济社会和电网不断发展,10kV配电系统容量小、损耗大、布点密、占地多等缺点日益突出,推广应用20kV供电是江苏省电力公司转变配网发展方式所作出的一项战略性决策,本文对镇江句容经济开发区采用20kV试点的经济性进行了详细分析,证明了20kV配电网在经济上的优越性。     

运动生化原理在110m跨栏教学与训练中的运用

在发展学生110m速度能力训练中依照能量供应系统的原理，收到了显著效果，促进了学生110m跨栏跑成绩的提高，说明运动生化原理对指导跨栏速度训练具有重要的作用。     

Effect of Si on austenite stabilization,martensite morphology,and magnetic properties in Fe-26%Ni-x%Si alloys

The effect of Si on the austenite stabilization, martensite morphology, and magnetic properties in Fe-26%Ni-x%Si (x=3.5, 5, and 6) alloys have been studied by means of transmission electron microscopy (TEM) and M?ssbauer spectroscopy techniques. TEM observations reveal that the martensite morphology is closely dependent on the Si content. The volume fraction changes of martensite and austenite phases, the hyperfine magnetic field, and isomer shift values have been determined by Mssbauer spectroscopy. The M?ssbauer study reveals that the hyperfine magnetic field, the isomer shift values and the volume fraction of martensite decrease with increasing Si content.     

论企业的社会责任

一、企业社会责任的概念 企业的社会责任，这一概念在20世纪20年代，随着资本的不断扩张而引起一系列社会矛盾，诸如贫富分化、社会贫困，特别是劳工问题和劳资冲突等而被广泛提出。20世纪80年代，企业社会责任开始在欧美发达国家逐渐兴起。1996年6月欧美的商业组织及相关组织召开了制定企业社会责任规范的初次会议。     

3000m障碍跑场地设计的一种新方案——牛顿迭代法在场地设计中的应用

本文用牛顿迭代法求得3000m障碍跑第二弯道所需设计线应对圆心角的弧度和圆的半径,给障碍跑场地的设计和测画提供了理论依据。